Instrument casing for measuring and controlling apparatus



W. P. WILLS INSTRUMENT CASING FOR MEASURING Nov. 6, 1951 2,574,203

AND CONTROLLING APPARATUS LA UI 2 SHEETS- SHEET l FIG. I

Filed May 3l, 1947 JNVENTOIL A WALTER P. wlLLs ATTORNEY.

NOV 6, 1951 w. P. wlLLs 2,574,203 l INSTRUMENT cAsING MEASURING ANDCONTROLLING PARATus Filed may s1, 1947 2 SHEETS-5mm 2 FIG. 4

INVENTOR. WALTER P. Wl LLS BYMWQW AT TOR NEY.

Patented Nou.

INSTRUMENT CASING FOR MEASURING AND CONTROLLING APPARATUS Walter P.Wills, Philadelphia, Pa., assignor, by mesne assignments, toMinneapolis-Honeywell Regulator Company, Minneapolis, Minn., a

corporation of Delaware Application May 31, 1947, Serial No. 751,522

2 Claims.

The present invention relates to measuring and controlling instrumentswhich are selectively adjustable by authorized persons only for eithermanual or automatic regulation of the application of a controllingmedium to a variable condition.

A general object of the invention is to provide measuring andcontrolling instruments of the above mentioned type in which themanually and automatically operable mechanisms while separable, are soarranged in association with each other that only authorized personshave access to said mechanisms for selectively eiecting automatic ormanual operation and/or for removing the automatically operablemechanism for repair or other purposes without interfering with theoperation of the manually operable mechanism in effecting its conditionregulating function.

In automatically operable control systems it is desirable and in somecases necessary to make some provision for effecting manual control ofthe condition. The manual control mechanism may be used when thecondition or system under control is first plac'ed into operation andwhile the variables being regulated are brought to a normally desiredvalue. It is also desirable to use the manual control mechanism when anupset occurs in the system or condition or any one or morev of severalrelated variables are being changed. Accordingly, it is desirable toprovide mechanism by means of which manual as well as automatic controlmay be effected.

In accordance with the present invention, the mechanism for effectingautomatic regulation of the iiow oi a controlling medium to the variablecondition is contained within an instrument case which is provided witha normally locked door. The mechanism for effecting manual regulation ofthe flow of the controlling medium to the variable condition is arrangedfor mounting immediately below the instrument case and is recessed so asto receive a downwardly extending portion of the door of the instrumentcase. The adjustment devices provided on the manual control mechanismare arranged substantially flush with the recessed surface of the manualcontrol mechanism so as not to interfere with the closing of the door ofthe instrument case. By virtue of this arrangement, the adjustmentdevices of the manual control mechanism are unavailable for unauthorizedor accidental adjustments when the door of the instrument case islocked. Furthermore, the shielding of the adjustment devices of themanual control mechalis nism by the downwardly extending portion ofinstrument door serves to substantially improve the appearance of themeasuring and controlling instrument mechanism as a whole by covering upthe adjustment devices of the manually operable mechanism.

Thus the invention in its preferred form is of especial utility inconnection with instrumentalities enclosed in a casing provided with anormally locked door which must be unlocked from time to time by anauthorized person to permit access to the vcasing interior for recordchart replacements or other purposes. Upon opening of the door, theadjustment devices of the manually operable mechanism are exposed foradjustment. It is a feature of the invention that since the manuallyoperable mechanism is separate from the instrument casing containing theautomatically operable mechanism that the latter may be removed forrepair or other purposes, the manually operable mechanism then beingutilized to eiect the necessary regulation of the ilow of controllingmedium to the variable condition under control.

The various features of novelty which characterize this invention arepointed out with particularity in the claims annexed to and forming apart of this speciiication. For a better understanding of the invention,however, its advantages and specific objects obtained with its use,reference should be had to the accompanying drawings and descriptivematter in which is illustrated and described a preferred embodiment ofthe invention.

Of the drawing:

Fig. 1 is a front elevation of the measuring and controlling arrangementof my invention, showing the door of the instrument casing closed;

Fig. 2 is a side elevation of the measuring and controlling instrumentarrangement of Fig. 1 and shows the instrument arrangement mounted onpanel;

Fig. 3 is a bottom view of the measuring and controlling instrumentarrangement of Fig. 1; and

Fig. 4 is a view showing the measuring and controlling arrangement ofFig. 1 with the door open.

Referring now to the drawing, the numeral l represents the body of aninstrument casing which is rectangular in outline and is provided with adoorway normally closed by a rectangular front door 2. The latter isconnected at the right side, as seen in Figs. 1 and 4, to the casingbody by hinges (not shown) and is provided at its left side with a lockwhich is adapted to be released by a key inserted in a keyhole 3 whichas shown is formed in the doorknob l. The casing body I is provided withupper and lower ledges la and Ib which are of the proper depth topresent a flush surface with the door 2 when the latter is closed. Thedoor 2 includes a glass panel 5 through which may be seen a circularrecord chart 6, a recording pen 1 and a control index 8.

The front door 2 includes a downwardly extending part 9 which issomewhat narrower than the door 2 and is symmetrically arranged withrespect thereto. The downwardly extending dimension of the door part 9is substantially the same as the width of a manual control mechanism orso-called by-pass panel which is represented by the numeral I0. Asshown, the bypass panel I is mounted directly beneath the instrumentcasing body I, with the upper edge thereof in physical engagement withthe lower sideof the ledge Ib of the instrument casing body I. The frontsurface of the by-pass panel III is recessed so as to accommodate thedownwardly extending door part 9 whereby the door 2 with its downwardlyextending part 9 and the front surface of the manual by-pass panel I0 oneither side of the recessed portion thereof present a continuous flushlor smooth surface of extremely pleasing appearance.

It is noted that the meeting of the upper edge of the door part 9 andthe lower edge of the door 2 completes a straight line, represented bythe numeral II, which extends across the width of the instrument casingarrangement. For the purpose of 'adding to the aesthetic beauty of theinstrument casing arrangement, a second line as shown at I2 and parallelto the line II may be engraved or otherwise cut into the surface of thedownwardly extending door part 9. This line I2 together with the linesformed on both sides of the door part 9 by the meeting of the upper edgeof the by-pass panel I0 and the lower edge of the ledge Ib also extendscompletely across the width of the instrument casing arrangement.

Referring to Fig. 4 it will be seen that the manual by-pass panel I 0 isprovided with manually rotatable knobs I3 and I4 and also with aninstrument I5 which may comprise a pressure gauge. In accordance withthe preferred embodiment of the invention, the instrument mechanismarrangement is arranged for either manual or automatic regulation of acontrol pressure to a control device such as a pneumatic operated valve(notl shown) although it will be evident to those skilled in the artthat the present invention is not limited in its application for usewith pneumatic control systems but may be utilized with equal facilitywith electric or hydraulic control systems, if desired.

The knobs I3 and I4 and the instrument I5 are all so arranged as to besubstantially flush with the surface of the recessed portion of thebypass panel I0. The knob I 3 is arranged in association with an arrowI6 which is engraved or otherwise formed on the recessed portion of theby-pass panel I0 and is adjustable into four different positions whichare designated on the knob as Aut0, Manual, Test and Service Thus, byadjustment of knob I3 the instrument mechanism arrangement may beadjusted for automatic operation or may be aclusted for manualoperation. Manipulation of the knob I3 also permits adjustment of theinstrument mechanism arrangement into test or service conditions,

the need for which conditions are known to those skilled in the art andneed not be further f elaborated on herein. The knob I3 is mechanicallyconnected to and, when rotated, adjusts a transfer valve mechanism shownin dotted lines in Figs. 2 and 3 and represented'by the referencenumeral I3a. The details of the transfer valve mechanism |311, and theconnections thereof to an air supply source and to the mechanismcontained in the instrument body I form no part of the' presentinvention and thereforefurther description thereof is not believednecessary.

The knob I4 is provided for adjusting the application of a control airpressure to a control device such as an air operated valve and whenrotated in clockwise direction serves to increase that control pressurewhile rotation thereof in a counterclockwise direction serves todecrease that control pressure. To this end the knob I4 is mechanicallyconnected to and, when rotated, adjusts a suitable pressure regulatorwhich is. shown in dotted lines of Figs. 2 and3 and is represented bythe reference numeral Ila. 'Ihe instrument I5 is arranged to indicatethe pressure established by the pressure regulator Ila for the purposeof facilitating the adjustment of the air operated valve pressure'to adesired value. Further description of the pressure regulator Ila and theinstrument I5 is believed unnecessary since the details thereof forni.no part of the present invention.

As is shown in Fig. 2, the instrument casing body I is adapted formounting on a panel I1 by suitable fastening means indicateddiagrammatically at I8. The manual by-pass panel Ill is adapted forseparate mounting by suitable mounting means on the panel I'limmediately below the instrument body I with the uplle edge of themanual by-pass panel in engagement with the lower edge of the lowerledge Ib of the instrument casing body I. The mounting means for themanual by-pass panel are show, in Fig. 2 as comprising a screw I9extending through the panel I1 and received by a suitable tapprovided inthe panel I0.

By virtue of the separate mounting provisions for the instrument casingbody I and the manual by-pass panel I0, the instrument casing body I maybe removed from the panel I'I'`for repair or other purposes, if desired,without disturbing the position of the manual by-pass panel Il or itseffectiveness in accomplishing its manual regulating function. 'Ihisfeature of my inventron is of considerable practical importance since itpermits removal of the instrument casing body and the automaticallyoperable exhibiting and regulating mechanism contained therein to a workbench or other more convenient location for eiecting such repairsas maybe mecessary.

It permits also easy replacement of `the instru-` ment casing body I andthe mechanism therein contained by another similar instrument mechanism.

From the foregoing explanation, it is evident that the present inventionis adapted for use with any instrument mechanism arrangement comprisinga manually adjustable device employed in association with anautomatically operating mechanism, which manually adjustable mechanismis made accessible for adjustment upon opening of the door of theautomatically operable mechanism and where it is desirable to preventunauthorized or accidental adjustment of the manually adjustable device.Merely by way of example, it is noted that the particular lnstrumentillustrated in the drawing comprises -a self-balancing potentiometermechanism including a pen 'l which is automatically adjusted across thecircular chart 6 in accordance with the varying values of thethermocouple voltage or other quantity measured and that the adjustmentsof the pen l! relative to the control index 8 give correspondingadjustments to the apper valve of an air actuated control mechanismlocated in the instrument casing l. In the particular instrumentreferred to, the self-balancing potentiometric measuring mechanism is ofthe commercial type manufactured and sold by my assignee, The BrownInstrument Company, and which is disclosed and claimed in my copendingapplication, now U. S. Patent 2,423,540, tiled December 1, 1941, andbearing Serial No. 421,173. The air actuated control mechanism is of thecomercial type also manufactured and sold by my assignee and disclosedin the Moore Patent 2.125.081. That air actuated control mechanismincludes pressure gauges 2| and 22 which respectively indicate thepressure from the air supply source and the air pressure applied to theair operated control valve.

The said air actuated control mechanism includes a pipe connection tothe transfer valve I3a so that upon adjustment of the knob I3 to itsautomatic position the said air actuated mechanisin is made elective forregulating the application of a control air pressure to an air operatedvalve utilized to control the flow of a condition regulating medium.Upon adjustment of the knob i3 to its manual position, the air actuatedcontrol mechanism contained within the instrument casing is deprived ofits automatic regulating function and the control of the air pressure tothe air operated valve may then be accomplished by manipulation of theknob I4.

While in accordance with the provisions of the statutes, I haveillustrated and described the best forms of the invention now known tome, it

will be apparent to those skilled in the art that changes may be made inthe form of the .apparatus disclosed without departing from the spiritof the invention as set forth in the appended claims, and that in somecases certain features of the invention may sometimes be used toadvantage without a corresponding use of other features.

Having now described my invention, what I claim as new and desire tosecurel by Letters Patent is:

l. In combination, a casing formed with a doorway, a door normallyclosing said doorway but movable to open the latter, said door having apart extending beyond one side of said casing, and a panel arrangedexterior of said casing but positioned adjacent said one side thereof,said panel having a recessed portion on which manually actuableadjustment devices may be arranged, said recessed portion havingsubstantially the dimensions of said part of the door extending beyondone side of the casing, said panel being so positioned with respect tosaid casing that the door part extending beyond the casing is receivedin said recessed portion when the door is closed so that the deviceswhich may be mounted on the panel are covered and made inaccessible.

2. In combination, a casing formed with a doorway, a door normallyclosing said doorway but movable to open the latter, said door having apart narrower than the other parts of said door and extendingsymmetrically beyond one side of said casing, and a panel wider thansaid door part and of substantially the same height as said door partand arranged exterior of said casing but positioned adjacent said oneside thereof, said panel having a recessed portion on which manuallyactuable adjustment devices may be arranged, said recessed portionhaving substantially the dimensions of said part of the door extendingbeyond one side of the casing, said panel being so positioned withrespect to said casing that the door part extending beyond the casing isreceived in said recessed portion when the door is closed so that thedevices which may bernounted on the panel are covered and madeinaccessible.

WALTER P. WILLS.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PA'IENTS Name Date Petri Nov. 3, 1936 Ullman et al June13, 1944 Number

